Reptiles of Australia
The Frilled Lizard
The Australian frilled lizard is also known as the frilled dragon and frill-necked lizard. Its scientific name is Chlamydosaurus kingii. The frilled lizard belongs to the dragon family. Its Class is Reptilia, Order Squamata, Family Agamidae. Only one species is recognised but because of colour differences between the lizards in Queensland and those in Western Australia/Northern Territory, there is some conjecture that they may be separate species.
In 1825, the explorer John Edward Gray named the lizard. It is endemic to southern New Guinea and the north and north western parts of Australia. It favours dry forest and woodland areas with an open scrubby or tussocky understorey. Ninety percent of the animal's time is spent in the trees.
All four legs are long and slim and the hind legs are strong. It climbs and moves easily through the branches. Apart from coming together to mate, the lizard lives a solitary life. They come to the ground to feed on smaller lizards, cicadas, termites, ants and spiders. The frilled lizard is a most distinctive animal. Males are larger and measure about 0.9 metres from head to tail and weigh up to 870 grams. The tail accounts for about 65cm of the total length. Females are much smaller.
The scales which cover the body are generally grey-brown but match the surroundings. The males are more brightly coloured. The striped tail has a dark grey tip. The lining of the mouth and the tongue may be pink or yellow. Its 'frilled' name comes from the 'cape' which covers its shoulders. This thin but extensive fold of skin forms a scaly ruff surrounding the throat. When the lizard is frightened or threatened, the frill is raised, forming a stiff and imposing ruff behind the head. It resembles an open umbrella. When fully extended, the bright orange and red ruff measures from 24 to 34cm wide. As well as being part of the lizard's defence mechanism, it is believed the frill helps to regulate the temperature of the body. It may also help attract a mate.
When danger threatens, the lizard has several options. It is well camouflaged so may simply sink to the ground and 'freeze' in position, hoping it goes unnoticed. It may make a dash for a tree or hide under low vegetation. If cornered, it will try to bluff its way out of a dangerous situation. It will face its predator, spreading the legs wide. It will open the mouth wide, displaying the bright colours of the mouth and the sharp teeth. The frill rises and becomes stiff, making the animal appear much larger. It will hiss and thrash its tail, rear up on its hind legs and leap or jump at its aggressor.
If all this fails to deter its enemy, it will turn tail and bolt for the nearest tree. It runs on the hind legs. The long, skinny legs splay madly to each side. This bipedal motion has earned it the name of 'bicycle lizard'. The lizard presents a comical sight, running at full speed, on two skinny legs, with the mouth open and bright frill fully erect. The frilled lizard is not poisonous or harmful to people but it will bite in self-defence.
This reptile is diurnal, absorbing energy from the sun during the day. It is an insectivore, eating smaller lizards and mammals, spiders, ants and insects. During drier seasons, activity decreases and they choose larger trees with canopy perches. They are more active during the wet.
Mating occurs during the wet season between September and February or March. Males perform an elaborate dance when courting. If the female is receptive, she will bob her head and stay in the area. Males are very territorial, fiercely attacking other males that may encroach on their space. Fertilisation is internal and between 8 and 23 soft-shelled eggs are laid in an underground nest. Clutch size depends on the geographic region. The tiny eggs weigh only 3 to 5 grams each.
When egg-laying, preference is given to a coarse-grained sandy soil which has little in the way of grass and leaf litter around it. This leaves the ground open to sunlight which keeps the soil and the eggs warm through the day. The eggs hatch after 8 to 12 weeks and the young are instantly independent, hunting for their food and erecting their frill at will.
Predators of this quaint creature are dingoes, quolls, birds of prey such as eagles and owls, larger lizards and feral cats. Feral cats are a particular problem, especially where habitat reduction is rife in the south east parts of its range. They are not good public exhibits as they will rarely raise their frills in captivity and do not display well. They have lived up to 20 years in captivity.
The frilled lizard once featured on the Australian two cent coin before it went out of circulation.